The present invention relates to a system for the acquisition of data inscribed on a support. It more particularly applies to the acquisition of graphic data, such as characters, curves or all types of lines present on a reflecting or transparent support, whereby said data are monochromatic or polychromatic. The system according to the invention makes it possible to digitize graphic data on a support. It can also permit the acquisition of data in photometry, densitometry, etc.
The known system permitting the acquisition and digitization of graphic data can be placed in two categories. Systems of the television camera type can be placed in a first category. These systems function by scanning the zone containing the data to be acquired. They generally comprise a digitization system connected to the scanning circuit of the camera. Their resolution is not very high. The systems of the second category comprise a "pen" making it possible to point or prick data of a design disposed on a table having a matrix of wires or any other system making it possible to cross-rule the zone containing the graphic data to be acquired. Their coordinates are obtained from electromagnetic field variations caused in the matrix of wires by the pointer. Under human control, said coordinates are then transferred to a computer.
In the case of systems of this second category, the digitization of the graphic data is not automatic and can involve considerable errors, due e.g. to the parallax of the pointing or pricking by means of the pen. Moreover, with such systems, the acquisition of graphic data takes a long time, is difficult and is also expensive. Systems of the second category are unable to supply numerical data relating to the intensities of electromagnetic radiation emitter by the data to be acquired.